Question

решите системы уравнений способом подстановки​

Answer 1

$8x - 3y - 7 = 0 \ 3x + y - 9 = 0 \ \ 8x - 3( 9 - 3x) - 7 = 0\ y = 9 - 3x \ \ 8x - 3( 9 - 3x) - 7 = 0 \ 8x - 27 + 9x - 7 = 0 \ 17x - 34 = 0 \ 17x = 34 \ x = 34 div 17 \ x = 2 \ \ y = 9 - 3x = 9 - 3 times 2 = 9 - 6 = 3$

Ответ : (2;3)